The Lability of Riverine Particulate Organic Carbon Delivered to the Ocean

每年从陆地到海洋的大量有机碳在海洋中大部分消失了。这种损失的原因尚不清楚。根据该奖项，PI将研究河流颗粒有机物质损失的非生物和生物方面的脆弱性。工作将集中在密西西比河上，因为它展示了北美河流中最明显的颗粒有机物质沉积在海洋中的损失。光化学实验将在初步工作的基础上继续进行，表明微粒有机物质在太阳辐射水平下的显著溶解。将研究与金属循环的相互作用，以及各种其他物理化学变量。生化不稳定性将通过酶水解和细菌培养来探索。将审查季节性模式，以及淡水环境中沉积的影响。

The large annual flux of organic carbon from land to the ocean largely disappears in the sea. Reasons for this loss are not clear. Under this award, the PI will examine abiotic and biotic aspects of the lability to loss of riverine particulate organic matter. Work will focus on the Mississippi, as it demonstrates the clearest loss of particulate organic material of any North American river upon deposition in the ocean. Photochemical experiments will follow up on initial work showing significant dissolution of particulate organic matter subjected to solar levels of radiation. Interactions with metal cycling will be studied, as will a variety of other physicochemical variables. Biochemical lability will be explored via enzyme hydrolyses and bacterial incubations. Seasonal patterns will be examined, as will be the influence of deposition in freshwater environments.